Data centers typically involve a large number of rack-mounted servers that are housed together in cabinets. Cooling of such server racks and cabinets is a major problem, particularly as processors typically produce large amounts of heat. It has been found that for every 1 watt of power used for Information Technology, 0.5 to 2 watts of power are used for cooling the electronic components, and thus the need for cooling uses a very high percentage of the total IT power consumption. The power dissipation of high-performance CPU processors is predicted to exceed 150 W in the near future. The high-density packing of servers and the desire for lower CPU junction temperatures to achieve higher reliability of components means that thermal management of server racks is an increasing concern. Various solutions have been proposed, many of which involve large numbers of fans to keep a constant airflow over the electronic components. However, such solutions suffer from drawbacks associated with the power supply needed to power the fans, as well as reliability of such fans.
In a number of solutions, server cabinets are placed on a false floor with cool air from an HVAC system being supplied through the false floor to a vent in front of the cabinet. The cooling airflow is then drawn front-to-back through the cabinet using fans, and vented out to the back of the cabinet. With such arrangements, it is desirable to use a “hot-aisle/cold-aisle” arrangement so that server fronts are arranged facing one another so that two aisles can draw cool air from a single vent area, and so that the server backs also face one another. The hot air is then allowed to vent to air return units in the ceiling. This can lead to “hot spots” in the server room, however, much of the hot air can also mix with the cool air circulating in the room. Various solutions to such problems involve the use of baffles extending from the top of the server cabinet to the ceiling to try to prevent some of the mixing between the hot and cold air.
The maximum allowed temperature range for a server in a data center is 59 to 90 degrees Fahrenheit, while the recommended temperature is between 68 and 77 degrees Fahrenheit. As the known data center storage solutions typically allow some mixing of air prior to the air reaching the electronic components, data centers typically pump cold air at between 55 and 60 degrees Fahrenheit to account for the temperature increase in the air before it can act to cool the components. The American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) has suggested that it would be beneficial if cold air could be conveyed directly to servers without mixing with hot air, which would allow the cooled air to be provided from the air handler to be warmer while still allowing the server temperature to remain within the recommended standard temperature ranges.